import 'dart:async';
import 'package:audio_service/audio_service.dart';
import 'package:flutter/services.dart';

/// 自定义 AudioHandler，用于捕获媒体按键事件（例如蓝牙耳机双击）
class MyAudioHandler extends BaseAudioHandler {
  // 定义一个 StreamController 用于向 UI 发送自定义事件
  final StreamController<dynamic> _customEventController = StreamController.broadcast();
  bool _isDisposed = false;

  Stream<dynamic> get customEventStream => _customEventController.stream;

  MyAudioHandler() {
    _initializeHandler();
  }

  void _initializeHandler() {
    try {
      // 设置初始播放状态
      playbackState.add(PlaybackState(
        controls: [
          MediaControl.play,
          MediaControl.pause,
          MediaControl.stop,
          MediaControl.skipToPrevious,
          MediaControl.skipToNext,
        ],
        systemActions: {
          MediaAction.play,
          MediaAction.pause,
          MediaAction.stop,
          MediaAction.skipToPrevious,
          MediaAction.skipToNext,
          MediaAction.seek,
        },
        androidCompactActionIndices: const [0, 1, 2],
        processingState: AudioProcessingState.idle,
        playing: false,
      ));

      // 设置媒体元数据
      final item = MediaItem(
        id: 'deep_voice_audio',
        title: 'Deep Voice Audio',
        album: 'Deep Voice',
        artist: 'Deep Voice',
        genre: 'Speech',
        duration: const Duration(seconds: 1),
        artUri: null,  // 移除图片URI
        playable: true,
        displayTitle: 'Deep Voice Audio',
        displaySubtitle: 'Voice Assistant',
        displayDescription: 'TTS Audio',
        extras: const {'source': 'deep_voice'},
      );
      
      mediaItem.add(item);
    } catch (e) {
      print('初始化 AudioHandler 失败: $e');
    }
  }

  // 激活应用
  Future<void> _activateApp() async {
    if (_isDisposed) return;
    
    try {
      print('收到激活应用事件');
      _customEventController.add('activate_app');
      
      // 尝试将应用带到前台
      await SystemChannels.platform.invokeMethod('SystemNavigator.routeInformationUpdated');
    } catch (e) {
      print('激活应用失败: $e');
    }
  }

  // 更新播放状态
  void _updatePlaybackState({
    required bool playing,
    required AudioProcessingState processingState,
  }) {
    if (_isDisposed) return;
    
    try {
      playbackState.add(playbackState.value.copyWith(
        playing: playing,
        processingState: processingState,
        updatePosition: Duration.zero,
      ));
    } catch (e) {
      print('更新播放状态失败: $e');
    }
  }

  @override
  Future<void> play() async {
    print('收到播放命令');
    await _activateApp();
    _updatePlaybackState(
      playing: true,
      processingState: AudioProcessingState.ready,
    );
  }

  @override
  Future<void> pause() async {
    print('收到暂停命令');
    _updatePlaybackState(
      playing: false,
      processingState: AudioProcessingState.ready,
    );
  }

  @override
  Future<void> stop() async {
    print('停止 AudioHandler');
    _isDisposed = true;
    try {
      await super.stop();
      _customEventController.close();
      _updatePlaybackState(
        playing: false,
        processingState: AudioProcessingState.idle,
      );
    } catch (e) {
      print('停止 AudioHandler 时发生错误: $e');
    }
  }

  @override
  Future<void> skipToPrevious() async {
    print('收到上一曲命令');
    await _activateApp();
  }

  @override
  Future<void> skipToNext() async {
    print('收到下一曲命令');
    await _activateApp();
  }

  @override
  Future<void> seek(Duration position) async {
    print('收到跳转命令: $position');
    await _activateApp();
  }

  @override
  Future<dynamic> customAction(String name, [Map<String, dynamic>? extras]) async {
    print('收到自定义命令: $name');
    if (name == 'media_button') {
      await _activateApp();
    }
  }

  @override
  Future<void> onTaskRemoved() async {
    print('服务被系统移除');
    await stop();
  }

  @override
  Future<void> onNotificationDeleted() async {
    print('通知被用户移除');
    await stop();
  }
}